Bulk mail accounts for a significant portion of the mail delivered by the United States Postal Service. The post office offers reduced postage rates for mail that is pre-processed. Essentially, the United States Postal Service charges less postage if the sender makes it easier for the post office to deliver the mail. To qualify for reduced rates, the processed mail must meet certain criteria set forth in various postal regulations. These criteria include the features such as printing the POSTNET barcode on the pieces of mail and ensuring that the pieces have a clear zone that is free of printing.
Frequently, high-volume machines are employed to preprocess mail so that the mail qualifies for the reduced postage rates. These machines scan each piece of mail and attempt to read the address printed on each piece. If the address for a piece is read, the machine then prints the appropriate POSTNET barcode on the piece. However, often these machines reject many pieces because the address could not be read. This creates a significant volume of mail that typically is processed manually or using semi-automated techniques, both of which increase the cost of pre-processing the mail.